White light is made up of different colours, each of which has a different effect on plants. The growth rate of the crop can be influenced by using LED lights or coloured removable coatings. What effect do these colours have?
Blue
Blue light has the most energy per photon. Blue light is vital for various processes in the plant, such as the different steps in the mechanism of photosynthesis. For instance, stomata will open under the influence of blue light. Blue light also has an impact on the shape of the plant, as well as the length and size of the leaves and the formation of branches. Each crop reacts differently to blue light. Some plants remain more compact, for example.
Green
Green light is the least effective colour for photosynthesis at leaf level. The leaves reflect a part of the light and absorb the other part, which is why they are green. Because some green light is reflected, it will penetrate deeper into the crop. At high light intensity, this is an advantage, and green light can, therefore, be the most effective colour for photosynthesis for the whole crop. Green light also has an impact on the shape of the plant. The effect on the production and quality of the plant if green light is blocked still has to be investigated.
Red
Red light is the most effective colour for photosynthesis at leaf level because the least amount of heat is left unused. Additional red light results in a compacter growth compared with the use of far-red light.
Far-red
Far-red light provides heat, but also affects cell elongation. Increased levels of far-red light result in increased cell elongation compared with using red light. The two concepts of far-red light and infra-red light are often confused. Infrared light is pure heat radiation while far-red light is still visible as a weak red shimmering.
Led-manufacturers attending GreenTech:
Agrolux, 11.123
BSS Led 08.219
Certhon 08.316
Gavita 11.404
Heliospectra 11.500
Illumitex 08.104
Lemnis Oreon 11.129
Light4Food 11.220
Megaphoton (Zhuhai Relighting) 11.130
PARSource 11.700
Philips Lighting LED Horticulture 11.101, Read more about Philips Led
Sonneteck Lighting LLC 411J
Valoya 11.222
